2011 GA
Near-Earth asteroid
From Wikipedia, the free encyclopedia
2011 GA is a Near-Earth object and Apollo asteroid that passed close to the Earth on 15 October 2023. Due to its size and low MOID, it is classified as a potentially hazardous asteroid (PHA).
| Discovery[1] | |
|---|---|
| Discovered by | Mount Lemmon Survey |
| Discovery site | Catalina Mountains north of Tucson, Arizona, USA |
| Discovery date | April 1, 2011 |
| Designations | |
| 2011 GA | |
| MPO 200327 | |
Apollo  NEO, PHA, Earth crosser, Mars crosser | |
| Orbital characteristics[2] | |
| Epoch 21 November 2025 (JD 2461000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 12.63 yr (4614 days) |
| Aphelion | 2.86328 AU (428.341 Gm) |
| Perihelion | 0.73589 AU (110.088 Gm) |
| 1.79958 AU (269.213 Gm) | |
| Eccentricity | 0.59108 |
| 2.41 yr (884.44 d) | |
| 332.056° | |
| 0° 24m 29.768s /day | |
| Inclination | 9.82630° |
| 200.341° | |
| 109.694° | |
| Earth MOID | 0.00711963 AU (1,065,081 km) |
| Jupiter MOID | 2.5206 AU (377.08 Gm) |
| Physical characteristics | |
| Dimensions | 170–380 m[3] |
| 4.4 hours | |
| 20.7[2] | |
Observations
2011 GA was discovered on 1 April 2011 by Andrea Boattinti, who was working for the Mount Lemmon Survey. [4]
In the days just after the close approach, the asteroid was observed by the Goldstone Solar-System Radar.[5]
Orbit and physical characteristics
The orbit and size of 2011 GA makes it a potentially hazardous asteroid (PHA). 2011 GA passed within 0.01743 AU (2,607,000 km; 1,620,000 mi) of the Earth on 15 October 2023.[6] The asteroid also passed within 0.02494 AU (3,731,000 km; 2,318,000 mi) from Earth around 15 October 1977. For comparison, the distance to the Moon is about 0.0026 AU (384,400 km).
2011 GA has a rotation period of about 4.4 hours.[5] Radar images of the asteroid showed a smooth, regular shape.
The Jupiter Tisserand invariant, used to distinguish different kinds of orbits, is 3.826.[2]
